Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

The annotations already declare readOnlyHint=false, idempotentHint=false and destructiveHint=false, so the agent knows this is a non-idempotent mutation. The description adds genuinely new context by disclosing that wakes consume the monthly allowance, a quota cost not visible in structured fields. It does not say what happens after the wake (latency to come online, precondition like vehicle sleep state) or whether authentication/setup is required.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

Three short sentences, the purpose front-loaded, followed by the two decision-relevant facts (cached reads, quota cost). No filler or restatement of the title.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For a simple one-parameter mutation with no output schema, the description covers purpose, a usage exclusion, and quota cost, which is adequate. It leaves two notable gaps: the target parameter is unexplained, and the post-wake behavior (how long until the vehicle is reachable) is unstated, which matters for an agent chaining calls.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

The single parameter 'vin' has 0% schema description coverage and the description never mentions it, so nothing indicates it identifies the target vehicle or that it is technically optional in the schema. With one undocumented parameter the description should have compensated and does not.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description opens with a specific verb and resource ('Wakes the vehicle'), which is unambiguous. It implicitly distinguishes itself from the get_* read tools by noting that cached reads do not need a wake, though it never names a sibling tool explicitly.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

'Cached reads do not need a wake' gives an explicit when-not-to-use condition, which is exactly the kind of guidance an agent needs to avoid unnecessary wakes. It stops short of naming the alternative read tools or explaining what state the vehicle must be in before waking.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.